Hub



FIG. 1 is an isometric view a hub;

FIG. 2 is a top plan view thereof; and,

FIG. 3 a right side view thereof.

The bottom plan view of the hub is identical to the top plan view. The left side view is identical to the right side view.

The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a hub, as shown and described. 